Imagine diving deep beneath the ocean’s surface, where mysterious lights flicker and strange creatures with sharp teeth lurk. Welcome to the Twilight Zone! Your mission is to survive in these depths and make your way to the surface after dark to find food. But here’s the twist: you are a hatchetfish, and almost everything around you wants to eat you. Luckily, you have some special tools to help you: a unique body shape, shiny scales, and glowing spots on your belly. You’ll need a lot of skill and a bit of luck to make it through.
Your first challenge is to start your journey upwards. You have a special organ called a swim bladder that helps you control your buoyancy, which means you can float or sink as needed. As night falls, you fill it up, becoming less dense and rising toward the surface. You can’t swim very fast, but your narrow body helps you move quickly to avoid danger. This is important because predators can appear out of nowhere. For example, a fangtooth fish might be lurking below you. It has huge teeth compared to its body size, making it a fierce hunter. Its skin is ultra-black, reflecting almost no light, so it’s hard to see.
Luckily, your glowing belly helps you blend in with the faint light from above, making you nearly invisible to predators like the fangtooth. But watch out! A bright light in the distance could be a trap. It’s actually a lure from an anglerfish, trying to catch unsuspecting prey. You quickly swim away just in time as it snaps its jaws shut on another fish. That was a close call, but you’re almost at the surface.
In the deep sea, more than 90% of creatures can produce light, but only dragonfishes can make red light. This is important because red light doesn’t travel far in water, so most sea creatures can’t see it. Dragonfishes use this red light to spot prey without being seen. Even though you can’t see the dragonfish, your shiny scales help scatter light, keeping you hidden from view.
After several close encounters, you finally reach the Photic Zone, where sunlight penetrates the ocean. You’ve just joined the world’s largest migration, happening every night as trillions of creatures move from the depths to the surface to feed. Here, your sensitive eyes spot a feast of small crustaceans and jelly-like zooplankton. During the day, tiny plants called phytoplankton use sunlight to turn carbon dioxide into energy, forming the base of the ocean’s food web.
As you feed, bits of organic matter like skin, waste, and dead animals sink or are carried back down by creatures returning to the depths. This process helps lock away carbon from the atmosphere in the ocean for hundreds of years, reducing the amount of carbon dioxide that contributes to climate change. This is known as the biological carbon pump, and your role as a hatchetfish is crucial in this process.
Your first journey is complete, but you’ll need to repeat this trip every night for the rest of your life. As the sun rises, the surface becomes dangerous, and you must dive back into the shadows of the Twilight Zone to stay safe.
Gather materials like shoeboxes, colored paper, and small figures to create a diorama of the Twilight Zone. Include creatures like the hatchetfish, fangtooth, and anglerfish. Pay attention to details such as the glowing spots on the hatchetfish and the ultra-black skin of the fangtooth. This will help you visualize the unique adaptations of these deep-sea creatures.
In groups, create a role-playing game where you take on the role of a hatchetfish. Develop scenarios based on the article, such as avoiding predators or finding food. Use dice to determine outcomes and discuss strategies to survive in the deep sea. This will help you understand the challenges and adaptations of deep-sea life.
Choose a deep-sea creature mentioned in the article, such as the dragonfish or anglerfish. Research its adaptations, habitat, and role in the ocean ecosystem. Create a presentation to share with the class, highlighting how these creatures survive in the Twilight Zone. This will deepen your understanding of marine biology.
Create an interactive quiz using online tools to test your knowledge about the biological carbon pump. Include questions about how hatchetfish and other creatures contribute to this process. Share the quiz with classmates and discuss the importance of the carbon pump in combating climate change.
Use art supplies to create a piece that illustrates how light and camouflage work in the Twilight Zone. Focus on how the glowing belly of the hatchetfish helps it blend in with the light from above. Display your artwork in class and explain the science behind these adaptations.
You’re traveling deep beneath the ocean’s surface, where faint lights flicker and creatures with sharp teeth appear. You are now entering… the Twilight Zone. Your mission is to survive these depths and journey to the surface after sundown to feed. You may now pick your player. Just kidding—you don’t have a choice. You’re a hatchetfish, and almost everything else is trying to eat you. The tools at your disposal are a uniquely shaped body, shiny scales, and glowing spots on your belly. You’re going to need a lot of skill and a little luck.
Your first challenge is to begin your upward trek. Your swim bladder allows you to precisely control your buoyancy. Come nightfall, you slowly fill it up, becoming less dense and rising towards the surface. You can’t swim fast, but your narrow build makes you maneuverable. This is especially important since predators could spring out of the darkness at any moment. In fact, a fangtooth is gliding beneath you. It has a significant tooth-to-body size ratio. Food is hard to come by in the Twilight Zone, so predators have adaptations to make every attack count. The fangtooth’s skin is ultra-black, reflecting less than 0.5% of the light that hits it, making this fish particularly hard to spot.
Fortunately, the bioluminescent organs lining your belly are regulated to match the intensity and pattern of the faint light from the ocean’s surface. This counter-illumination disguises your silhouette. So when the fangtooth gazes upwards, you’re almost invisible. A bright spot appears in the distance. You go to check it out, but something’s looming in the darkness. The light is a bioluminescent lure belonging to an anglerfish. You dart away before it quickly opens its jaws, capturing a hapless fish that got too close. Another narrow escape, but you’re nearly there.
Although more than 90% of deep-sea creatures are bioluminescent, only one group produces the color red: dragonfishes. One of them is near. Because red light is quickly absorbed by seawater, most deep-sea inhabitants can’t see it. The dragonfish emits red light from organs near its eyes, using an invisible headlight to locate unsuspecting prey that it scoops into its cavernous jaw. You can’t see your enemy, but your silvery, mirror-like scales scatter and soften direct light, keeping you hidden.
After three close calls, you reach… the Photic Zone. You’ve just participated in the world’s largest migration. It takes place every night as trillions of organisms rise from the ocean’s depths to enjoy the surface’s rich resources under the cover of darkness. The payoff is huge. Here, your light-sensitive eyes take in a buffet of small crustaceans and gelatinous zooplankton. During the day, phytoplankton use sunlight to turn dissolved carbon dioxide into energy and build their own cells. They become food for small grazers, forming the base of the food web, which extends back down to the Twilight Zone—and beyond.
Organic matter generated up here—like bits of skin, waste, and dead animals—eventually sinks or is transported in the stomachs of animals returning from their nightly migrations. These materials then feed the creatures below that don’t migrate. This ensures that some of the carbon from the atmosphere is locked away in the ocean for hundreds of years to come. That’s why this process is known as the biological carbon pump. Without it, there’d be much more carbon dioxide in the atmosphere, where it contributes to climate change. Your avatar, the hatchetfish, is part of this crucial process.
Your first quest is complete, but you must repeat this journey every night for the rest of your life. As the sun rises, the surface becomes dangerous, and you descend back into the shadows of the Twilight Zone.
Ocean – A large body of salt water that covers most of the Earth’s surface and is home to many different forms of life. – The ocean is teeming with diverse marine life, from tiny plankton to massive whales.
Creatures – Living organisms, especially animals, that inhabit various environments on Earth. – Many fascinating creatures, such as jellyfish and sea turtles, can be found in the ocean.
Light – Natural energy from the sun that is essential for the process of photosynthesis in plants. – In the ocean, light only penetrates the upper layers, where most marine plants and animals live.
Predators – Animals that hunt and eat other animals for food. – Sharks are well-known predators in the ocean, feeding on fish and other marine animals.
Swim Bladder – An internal gas-filled organ that helps fish maintain buoyancy in the water. – The swim bladder allows fish to stay at their desired depth without expending much energy.
Buoyancy – The ability of an object to float in water or air. – Fish use their swim bladder to control their buoyancy and move up or down in the water.
Dragonfish – A deep-sea fish known for its bioluminescent properties and ability to survive in dark ocean depths. – The dragonfish uses its glowing body to attract prey in the pitch-black waters of the deep ocean.
Phytoplankton – Microscopic plants that live in the ocean and are a crucial part of the marine food chain. – Phytoplankton produce much of the Earth’s oxygen through photosynthesis.
Carbon – A chemical element that is a fundamental building block of life and is found in all living organisms. – Carbon is cycled through the environment in processes like photosynthesis and respiration.
Food – Substances consumed by organisms to obtain energy and nutrients necessary for growth and survival. – In the ocean, food chains often start with phytoplankton, which are eaten by small fish and other marine animals.
